Fluid regulators as such are well known in the state of the art. They are used to reduce the pressure of a fluid, entering the fluid regulator on a high pressure side, to a lower pressure level on the fluid outlet side. Preferably, the pressure on the fluid outlet side will be essentially constant. Such pressure regulating units are used, for example, for pressurized gas bottles (pressure cylinders), where the pressure of the gas inside the bottle of up to 300 bars (or even higher) has to be reduced to a lower pressure level of usually 3-10 bars, which can be handled better. In some applications, however, a reduced pressure on a level around 40-50 bars is desired. However, other lower pressures are also possible, like pressures in the area of 20 bars, 30 bars, 60 bars, 70 bars, 80 bars, 90 bars, 100 bars, 110 bars, 120 bars, 130 bars, 140 bars, 150 bars, 160 bars, 170 bars, 180 bars, 190 bars or 200 bars, to give some examples. Another example for the use of fluid regulators are fire extinguishers and/or fire extinguishing systems (fire fighting systems), which can be portable, mobile (built into a vehicle, for example) or stationary (built into a building, for example). Here, the supply of a fire extinguishing agent with a usually changing pressure level during use has to be reduced to lower pressure level with a preferably constant pressure. The fire extinguishing agent with the reduced pressure level can hence be expelled by an appropriate nozzle, for example.
For the fluid, not only gases are possible. Also, liquids (like liquid CO2, for example), supercritical fluids (where no distinction between the liquid and the gaseous phase is possible any more), and mixtures of liquids, supercritical fluids and/or gases are possible. Also, the fluid can even contain a certain percentage of solids (smoke and/or suspensions, for example).
The problem with the majority of presently existing pressure regulators is the usually high number of movable parts, necessary for the construction of the pressure regulator. Apart from the costs involved with manufacturing and arranging a large number of movable parts, this also gives rise to vibration problems. Such vibrations can lead to the generation of noise and a bad output pressure characteristics (i.e. randomly varying output pressure). Another problem is that in the majority of presently available pressure reducers, the fluid, which pressure has to be reduced, has to change its moving direction several times, when flowing through the pressure regulator. This can give rise to a slow pressure regulation response and therefore to a bad pressure output characteristics. The output characteristics of such a pressure regulator is usually particularly bad, if the fluid input reservoir becomes exhausted and the fluid inlet pressure is getting close to the fluid outlet pressure of the pressure regulator.
For improving the pressure output characteristics and reducing the vibration problems, so called “in-line” constructions have been proposed. In these “in-line” constructions, the number of directional changes of the fluid flowing through the pressure regulator is reduced. Furthermore, the number of moving parts can usually be reduced with in-line constructions. Therefore, in-line pressure regulators usually show less vibrations and a more constant, less fluctuating fluid output pressure.
Examples of pressure regulators, using the “in-line” design can be found in U.S. Pat. No. 2,777,458 and U.S. Pat. No. 3,890,999, for example. However, presently existing designs of in-line pressure regulators still suffer from a number of drawbacks. A major drawback, for example, lies in mounting the pressure regulator for the first time after delivery and in the delivery state of the pressure regulator itself. The problem lies in particular in that the pressure regulator usually is in an open state, when delivered from the manufacturer. This, however, can lead to the release of a too high pressure after mounting the pressure regulator. Furthermore, the pressure regulator can suffer damages during shipment, particularly if the valve of the fluid pressure regulator is shipped in an open position. Also, there are situations, in which it is desired that the pressure regulator can be cut off. With presently available fluid pressure regulators, usually a separate cut-off valve is needed for this.